/Engine/Plugins/Online/OnlineFramework/Source/Party/Public/SocialToolkit.h
Only handles accepting a friend request via the friends interface, assumes all checks are handled previously
virtual bool AcceptFriendInviteInternal ( const [USocialUser](API\Plugins\Party\User\USocialUser) & SocialUser, [ESocialSubsystem](API\Plugins\Party\ESocialSubsystem) SubsystemType ) const